Question

Write a c program that takes in a text file and writes lines with only lowercase letters to another text file which is disclosed from the command line. If no text file to output to is disclosed in the command line, the lines with only lowercase letters should be written into a text file called "all_lower.txt"

Answer 1

CODE ::

EXECUTION ::

RAW CODE :

#include <stdio.h>
#include <stdlib.h>
int main(int argc,char* argv[]){
   char str[2];
   if ( argc != 2 ){   // Checking the Command line Args
       printf("Usage : ./executable <Text file Name>\n");
       exit(0);
   }
   FILE *fp = fopen(argv[1], "r");
   FILE *new= fopen("all_lower.txt","w");
   if (fp == NULL){    // On Error means , File not Found
puts("File not Found!.....");
exit(0);    // Exiting  
}
// If File is there , WE read its chars one by one , Write them to new file
// BY converting Them to lower case
while (fgets(str,2, fp) != NULL){   // Read a single char, 2nd char is '\0'
   // Condition for the lower case are [ 65 - 90 ] <- Ascii values
   // Difference between the Upper and Lower is 32
   // Means lower + 32 -> Upper
if (65 <= str[0] && str[0] <= 90) str[0] += 32;
fprintf (new, str);   // Wtiting the Updated Char into the File
}
// Closing The files
fclose(fp);  
fclose(new);
}